Asked on CNBC's "Squawk Box" if he knew that the rollout of Healthcare.govwould be problematic, the insurer's CEO, Mark Bertolini, said his giant company's role as an alpha tester for the system gave it a sense of how many problems thehealth insurance marketplace faced on the eve of its launch.

"We were pretty nervous as we got further along," Bertolini said. "As they started missing deadlines, we were pretty convinced it was going to be a difficult launch."

His fears have been realized, he said, and the technological debacle seen at Healthcare.gov is one similar to just the handful he's witnessed in his career.

"It's nothing you ever like to repeat," Bertolini said. "Because it's very difficult. I've been there. It's career-ending in a lot of cases." . . .